EP0783748B1 - Applications, dans le stockage de grande capacite, de matrices de sondes locales - Google Patents

Applications, dans le stockage de grande capacite, de matrices de sondes locales Download PDF

Info

Publication number
EP0783748B1
EP0783748B1 EP95925091A EP95925091A EP0783748B1 EP 0783748 B1 EP0783748 B1 EP 0783748B1 EP 95925091 A EP95925091 A EP 95925091A EP 95925091 A EP95925091 A EP 95925091A EP 0783748 B1 EP0783748 B1 EP 0783748B1
Authority
EP
European Patent Office
Prior art keywords
storage
medium
storage device
information
erased
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP95925091A
Other languages
German (de)
English (en)
Other versions
EP0783748A1 (fr
Inventor
Gerd Karl Binnig
Heinrich Rohrer
Peter Vettiger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0783748A1 publication Critical patent/EP0783748A1/fr
Application granted granted Critical
Publication of EP0783748B1 publication Critical patent/EP0783748B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y15/00—Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/02—Analogue recording or reproducing
    • G11B20/04—Direct recording or reproducing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • G11B27/327—Table of contents
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B9/00—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor
    • G11B9/12—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor using near-field interactions; Record carriers therefor
    • G11B9/14—Recording or reproducing using a method not covered by one of the main groups G11B3/00 - G11B7/00; Record carriers therefor using near-field interactions; Record carriers therefor using microscopic probe means, i.e. recording or reproducing by means directly associated with the tip of a microscopic electrical probe as used in Scanning Tunneling Microscopy [STM] or Atomic Force Microscopy [AFM] for inducing physical or electrical perturbations in a recording medium; Record carriers or media specially adapted for such transducing of information

Definitions

  • the present invention relates to storage devices based on local probe arrays and appropriate storage media.
  • a scanning tunneling storage system has been proposed in the European patent EP 247219. This system comprises current detectors being attached to an array of cantilevers. A storage medium is placed opposite to the array. The storage medium is displaced by means of a two-dimensional piezoelectric positioning device. There is no adequate approach for erasing of information disclosed.
  • steps US-A-5 036 490 discloses a storage device according to the preamble of claim 1, wherein means for erasing a whole section of the storage medium are provided. required to erase information being stored in such a material are either to slow, or cannot be controlled properly to facilitate erasure of single bits within a storage medium.
  • Said storage device further comprises
  • Cantilevers are well known elements which are easy to make. Existing semiconductor fabrication processes can be employed. In essence, the techniques of micromachining are employed to create discrete cantilevers and arrays of cantilevers. When dimensioning such cantilevers, one has to take into account specific parameters of the material used as substrate in which the cantilevers are formed. When properly designing such an array, it can be mass-produced at low cost and with high yield.
  • cantilevers and cantilever arrays are made by etching away portions of a silicon substrate.
  • This substrate is normally (100) or (111) oriented.
  • (100) oriented silicon could for example be wet etched using ethyl diamine pyrocatechol or KOH solutions.
  • Wet etching techniques are generally dependent on crystallographic orientation of the substrate, e.g. (100) oriented silicon shows a very low etch rate of the (111) plane, leading to a good etch stop along the (111) axis which generates well defined etch planes with 54.7 ° angles from (100).
  • An alternative approach makes use of dry etching techniques, e.g.
  • RIE reactive-ion beam etching
  • chemically assisted ion beam etching or microwave assisted plasma etching.
  • microwave assisted plasma etching Depending on process conditions, deep and anisotropic structures can be obtained leading to excellent dimensional control.
  • Masks can be employed to define the structures to be etched.
  • the cantilevers used can have any shape that can be obtained by photolithography and etching.
  • the cross-sectional shape could for example be rectangular, round, elliptical, or polygonal.
  • cantilevers are also suited for the fabrication of cantilevers, like gallium arsenide, as reported in "dynamic Micromechnics on Silicon: Techniques and Devices", K.E. Petersen, IEEE Transactions on Electronic Devices, Vol. ED25, No. 10, 1978, pp. 1241 - 1249.
  • a tip is used as local probe.
  • Different techniques are known to produce such tips. They can for example be made by isotropic wet or dry etching in combination with the oxidation of a single crystal material such as silicon.
  • the following materials are well suited for making local probes and local probe arrays: tungsten, tungsten alloy, platinum, molybdenum, silicon (doped or undoped), doped diamond, any refractory metal, or conductive ceramics, to name some.
  • the combination of wet or dry etching and liftoff plus oxidation leads to very sharp pointed cones. The sharper the tips are, the denser information on a storage medium can be stored, i.e. the higher the storage capacity of a storage device will be.
  • the probes can be coated with an appropriate metal such as gold, for example.
  • an appropriate metal such as gold
  • US patent 5 204 581 it is described in detail how to make tips or arrays of tips which can be used in connection with the present invention.
  • Another example for the microfabrication of a tip is disclosed in the article "Silicon cantilevers and tips for scanning force microscopy", J. Brugger et al., Sensors and Actuators A, Vol. 34, 1992, pp. 193 - 200. It is important to note that by means of batch fabrication local probe arrays can be made in a reproducible and cheap manner.
  • Certain means including driving circuitry, preamplifiers, and an appropriate wiring for reading and writing information need to be provided.
  • the driving electronics as well as the probes call for circuitry like that used in scanning tunneling microscopy (STM) and atomic force microscopy (AFM) systems, albeit shrunken to extremely small size.
  • STM scanning tunneling microscopy
  • AFM atomic force microscopy
  • the miniaturization is mandatory to obtain short interconnections, high speeds, and less power for circuitry.
  • a storage medium in accordance with the present invention is partitioned into storage fields in which the information is actually stored.
  • the media which can be used in connection with the present invention can be grouped as follows. In general, perturbations can be formed in a medium, or removed therefrom by locally
  • Perturbations can also be generated by employing the tunneling effect in order to move and remove atoms.
  • This approach according to which the information is stored in the form of patterns of atoms adsorbed on the surface of a storage medium, is described in US patent 4 575 822.
  • the probe is maintained at tunneling distance from the medium to remove individual atoms from the medium for writing, and to detect variations of the tunneling current caused by the presence or absence of atoms in scanned locations for reading.
  • nitride-oxide-silicon media As shown in connection with the first embodiment of the present invention, Either a scanning tunneling tip, or a scanning capacitance probe placed at a certain distance with respect to the nitride-oxide-silicon medium can be used to measure and to detect perturbations. Further details are given in the article "Charge storage in a nitride-oxide-silicon medium by scanning capacitance microscopy", R.C. Barrett et al., Journal of Applied Physics, Vol. 70, No. 5, 1 Sept. 1991, pp. 2725 - 2733.
  • temporary storage media In addition to permanent storage media, temporary storage media are known.
  • One example is a medium in which electric charges are trapped when writing information into it. After a while this information disappears because the electron charges get spread out.
  • a material which shows such a behavior could also be used in connection with the present invention, as will be described later.
  • Beneath STM based approaches AFM techniques which are capable of seeing contrasts (perturbations) on insulating and magnetic storage media without using any electrical currents, or any combinations of AFM and STM can be used.
  • the different storage media can be structured so as to provide separate storage fields thereon. These fields are arranged such that they do not overlap. Usually there is a certain distance left between neighboring fields to ensure that the data of the respective fields are clearly distinguishable. The more densely these storage fields can be arranged, the higher the storage density of the overall storage device are.
  • the simplest approach is to move either the whole local probe array while the storage medium's position remains unchanged, or the other way around.
  • An additional degree of freedom can be achieved if the storage medium and the local probe array are moved. It is, for example, advantageous to slowly move the storage medium back and forth in a direction parallel to a first axis.
  • the scan excursion of the storage medium is chosen such that the local probes do not exceed the corresponding storage fields, i.e. the scan excursion is approximately equal to the dimension of the storage fields.
  • the local probe array is step-wise moved perpendicular.
  • tracking can be achieved by providing special tracks at the edges of the storage medium which are watched and followed by the moving local probe array.
  • Tracking can for example be achieved by mechanical means which guide the local probe array along a predefined direction.
  • Such mechanical tracking means can be combined with, or completely replaced by, optical or other contactless tracking means.
  • Deflection sensors on the local probe array which are arranged such that they interact with counterparts on the storage medium, allow to precisely move the array parallel to the storage medium.
  • Special tracking marks can be used to mark the boundaries of the storage fields and/or storage medium. If such a tracking mark is reached the local probe array can be triggered to move backwards, or to jump to another position, for example.
  • Tracking is also important to ensure that the storage device will return into a well defined position after power-off or after it has been parked.
  • each local probe or the cantilever on which it is situated might have its own actuator.
  • Each such actuator needs appropriate wiring and driving circuitry.
  • Two different schemes are conceivable if one employs such semi-autonomous local probes: 1) the local probe actuators can be used to compensate fabrication tolerances and to level out local surface roughness of the storage medium; 2) The local probes themselves might contribute to the scan movement in which case more complex local actuators are required. If such local probe actuators are employed, one might also envision to provide tracking on a storage field basis. One example would be to arrange a long chain of atoms along a row such that these atoms can be detected and followed by the local probe.
  • Each of the cantilevers might comprise an actuator so as to displace it from a relaxed position to a deflected position or vice versa.
  • the displacement achieved by an actuator might be damped to prevent damage, for example.
  • a coarse macroscopic distance adjustment might be required, depending of the particular application.
  • a coarse actuator might be employed to move the probes of an array within reach of the storage medium and the fine actuator means of the cantilevers then provide the operating gap control.
  • Coarse displacement can be used to compensate manufacturing tolerances, to move the array in a park position when not being used, or while a certain area is erased in accordance with the present invention.
  • coarse displacement PZT a piezoelectric ceramic material; Lead Zirconate Titanate
  • precision levers and micrometer screws can be used.
  • the above mentioned actuators need specific driving circuitry which can either be integrated into the present storage device, or which can be carried out separately. It is important that the scan movement is synchronized with the multiplexers/demultiplexers used for reading and writing of data.
  • an interface circuitry In addition to the driving means and read/write electronics kind of an interface circuitry is needed.
  • a circuitry might include a microprocessor, multiplexer/demultiplexer, parallel-to-serial converters and serial-to-parallel converters, digital/analog and analog/digital conversion circuits and so forth.
  • error correction means For some applications it is advisable to employ a microprocessor which coordinates all activities of the storage device. It is likewise conceivable to design the present storage device such that it cooperates with the microprocessor of a computer of which the storage device is a part. Very fast electronic or optical switches might be employed to cope with the huge amount of data accessible through hundreds or thousands of local probes of the present storage devices.
  • a storage field 11.1 comprises small perturbations in the storage medium 10. Each of these perturbations represents a bit. Such perturbations can be very small. Perturbations having a size of a few nm were reported in the art. To ensure that such perturbations can be easily detected, the centers of neighboring perturbations should be about 30nm apart.
  • a storage field in accordance with the present invention might have a size of 30 ⁇ m x 30 ⁇ m leading to a storage density per storage field of 10 6 bits.
  • a sub-array of four storage fields 11.1 - 11.4 is shown. 4 ⁇ 10 6 bits can be stored in such a sub-array.
  • a bit scan speed (read-out speed) of about 100kHz per tip can be achieved.
  • a local probe array with four cantilevers 13.1 - 13.4 with the respective tips is scanned as a whole over the corresponding storage fields 11.1 - 11.4 and the data in each storage field are addressed quasi-simultaneously.
  • a displacement of the array in the direction perpendicular to the medium might be useful, e.g. when parking the array.
  • the maximum lateral scan excursion of a tip depends on the dimension of a single storage field. In the present example, the maximum scan excursion is ⁇ 30 ⁇ m.
  • an access time in the range of 1 ms to 1 ⁇ s can be achieved. This compares very favorably with present day disc drive access times of about 10 ms.
  • a total data rate of 4 ⁇ 10 5 bits/s can be obtained (assuming 10 6 bits/storage field, 4 fields and 100kHz scan speed), of course, these numbers scale with the the scan speed and the number of storage fields.
  • the local probe array 20 comprises metallized cantilevers 13.1 - 13.4 and tips.
  • the storage medium consists of a semiconducting substrate 10 covered by a thin oxide layer 15. This oxide layer 15 is coated with patterned dielectric layers 11.x. The size and shape of these dielectric layers 11.x define the storage fields.
  • the cantilevers 13.x are designed such that the tips are pressed against the storage fields. When scanning the whole array 20 over the storage medium 10, the tips are used to measure the electrical properties of the corresponding storage fields.
  • the local probe array of a storage device in accordance with the first embodiment can be simply addressed by four X-Y access lines, respectively, which enable read/write of the local probe in a chosen storage field at a bit position within this storage field given by the momentaneous position of the local probe array.
  • N 2 X-Y access lines would be needed.
  • Well suited as storage medium is a combination of silicon as substrate 10 with nitride as dielectric layers 11.x.
  • information can be stored in form of charges which are trapped in the nitride layer.
  • Charges are introduced, i.e. written, by applying a bias to the respective tip. This causes charges to tunnel through the oxide layer 15 and to become trapped in the nitride layer 11.x.
  • These perturbations in form of charges have been observed to be stable over a period of several days.
  • the perturbations can be detected, i.e. read, either by using the tips of the local probes, or by obtaining a capacitance image of the storage fields using the metallized cantilever.
  • the perturbations can be largely removed, i.e.
  • the tips can be reverse biased and moved slowly over the storage fields, or additional means can be provided to remove these charges.
  • Neighboring storage fields could for example be cleaned-up separately, if there are separate contacts to the storage medium's backside and if neighboring storage fields are sufficiently isolated from each other. This allows to apply a revered bias to one storage field while writing information into an adjacent field.
  • FIG. 3 An example is illustrated in Figure 3.
  • a top view of a storage medium 30 with several storage fields 31 is depicted. Before the storage field 31 is erased, all information in this field which is still needed is transferred to another, empty field 32. Likewise, a conventional memory device might be employed for storing such information which is still needed.
  • the present storage device comprises means which help to distinguish information which is not longer needed from information which is still needed. This can be done by means of a table maintained in a reserved, separate storage field 33, or by reserved bits, e.g. at the side of each storage field.
  • a storage field 40 is shown which comprises 25 bit locations, for example. Assuming that two of these bits, see reference numeral 41, are still needed, whereas all other bits are not longer needed, these two bits have to be marked appropriately.
  • RF row flags
  • CF column flags
  • the first and second bits 43 of the CFs 45 are raised (e.g. 'one') and the second flag 42 of the RFs 44 is raised, too.
  • the CFs 45 are rotated and placed nexl to the RFs 44.
  • the flags of the CFs 45 point to the respective rows and the flags of the RFs 44 point to the respective columns of the storage field 40.
  • the advantage of this arrangement is that the flags can be read concurrently with the bits in the storage field, provided that there is an array of parallel levers 47 probes 46, as depicted in the cross-sectional view given in Figure 5A.
  • An alternative approach would be to mount all these parallel probes 46 at the end of one and the same cantilever. In this case additional means have to be provided which give each probe some freedom of movement along the z-axis in order to level out surface roughness of the storage medium.
  • the data on the storage medium can be arranged in an interleaved manner. If one assumes a distance between neighboring tips of 300nm the 1st, 11th, 21st, 31st and so forth columns would be read concurrently. Then, the probe array 46 is moved 30nm and the 2nd, 12th, 22nd, 32nd etc. are read.
  • each bit word in the storage field could comprise a header indicating whether the information comprised in the word is still needed.
  • erase pointers The means used to indicate what part of the information in a storage field is still needed is hereinafter referred to as erase pointers and the process used to distinguish between information which might be used later and information not longer used is called erase data management.
  • erase pointers In case that one uses a column and row flag for each bit, much real estate on the storage medium is wasted for these erase pointers. Depending on how the information in a storage field is organized, less erase pointers are needed.
  • Figure 6 an example of five 8-bit words within a storage field is illustrated.
  • an error detection mechanism might be applied to check whether information got corrupted. Any kind of error detection mechanism, like cyclic-redundancy check, can be employed.
  • a storage field is searched for information not longer needed using the respective erase pointers.
  • the information which is still needed is then transferred into another, blank storage field.
  • this transfer of information is done geometrically, i.e. blank areas in originating storage field are copied and appear as blank areas in the destination storage field on a bit-by-bit basis.
  • a compression mechanism fuzzy puzzle clean-up starts searching for files or words from other storage fields or sub-arrays that fit well into the blank gaps in the destination field. Due to the fact that there are hundreds or even thousands of different storage fields, the probability to find such words or files is very high.
  • a destination field is now packed until its storage capacity is almost, or in some cases even totally used up.
  • the data compression can be further improved or modified, for example, by applying certain rules for the selection of a storage field which is to be emptied. This field could be selected by comparing the amount of obsolete data of a field with the amount in other fields.
  • the storage field with most obsolete data i.e. the field where only a few bits are still needed, can be treated first. Then the next storage field follows, and so on.
  • the rules for cleaning-up certain storage fields can either be user-defined, or can be implemented when designing a storage device.
  • the storage capacity needs to be sufficiently high.
  • a storage medium 70 with many storage fields 71 is used.
  • the storage medium 70 carries 1000 x 1000 storage fields 71, each storage field having a capacity of 10 6 bits. This leads to a storage device which is capable of storing up to 1 Terabit.
  • a two-dimensional local probe array 72 having 1000 x 1000 cantilevers 73 and probes is provided. This two-dimensional array 72 of cantilevers is placed at a close distance to said storage medium 70 and a probe is assigned to each storage field thereof.
  • the storage device makes use of the tunneling effect for reading and writing of information.
  • an appropriate wiring is needed. If the storage medium 70 is kept on ground potential by using a common contact to its backside, there is one access line per probe required. This assumption only holds if the cantilevers do not require active positioning means, such as fine actuators for z-displacement. The real estate on the substrate of the 2-dimensional local probe array 72 would not be sufficient to carry the 1000 2 access lines. According to the present invention this problem is circumnavigated in that said storage device comprises another layer 74, referred to a level 3, which is flipped onto the substrate with cantilever arrays 72.
  • This level 3 carries the read/write lines 75.x, and select lines 76.x and, if space permits, additional electronic read/write circuitry, for example.
  • the employment of read/write lines 75.x and select lines 76.x requires a multiplexed addressing scheme which will be described in detail in connection with Figure 9.
  • the three levels of the present storage device are only illustrated schematically in Figure 7.
  • solder bonding which is normally used to connect several printed boards, is well suited to be used in connection with the present invention. The alignment accuracy which can be achieved is sufficient to realize high density storage devices in accordance with the present invention. In addition to using the solder bonds for alignment and mechanical interconnection, these bonds can serve as electrical connections between the local probe array and the board 74.
  • capacitive electrical coupling from level 3 to level 2.
  • the embodiment illustrated in Figure 7 comprises the following materials and the read/write process is based on the below described approach.
  • the storage medium 70 comprises a ferroelectric material, e.g. PZT, which is locally polarized by means of a probe of the local probe array 72.
  • Well suited are thin film ferroelectric materials.
  • the storage medium retains a local remanent polarization after the tip is moved forward to a next bit position. A reverse polarization voltage applied would polarize the medium in the opposite direction. This effect could be used for bistable storage devices having a higher storage density.
  • the local polarizations are non-volatile, i.e. remain unchanged if the local probe is moved away.
  • the perturbations in form of a local polarizations can be detected, i.e.
  • the tip of the local probe array 72 are operated in the field emission mode instead of the tunneling current mode used for reading and writing. In the field emission mode larger voltages or currents can be introduced to the storage fields. This approach is not well suited for bit-by-bit erasure of information because it has a reduced resolution and is slower.
  • the field emission mode is used for cleaning-up whole fields. This process of cleaning-up is controlled and carried out by special data management means, already mentioned in connection with the first embodiment.
  • FIG 8 part of another storage medium 80 is shown.
  • This storage medium is partitioned into several sub-arrays 81.
  • Each such sub-array has a great number of storage fields 82 (see magnified sketch) as for example described in connection with Figures 1, 2, or 7.
  • One local probe array is now assigned to each of the sub-arrays 81.
  • These local probe arrays are mechanically independent so that some sub-arrays can be in a read/write mode while others are are parked or flipped away so that the storage fields underneath can be cleaned-up.
  • Each of the sub-arrays might have its own read/write electronics and multiplexers/demultiplexers.
  • Higher level data management means are provided to control data flow between sub-array, to redistribute incoming data if some sub-arrays are currently not available or accessible, and so on.
  • EDC Error detection and correction
  • each sub-array making it capable of detecting single or double bit errors and correcting single bit errors. This is preferably done by appending one byte of error correcting code (ECC) to each 4 bytes of memory.
  • ECC error correcting code
  • a storage device with N x N storage fields and N x N local probes requires N 2 address lines.
  • a storage device with 1000 x 1000 local probes would require 10 6 address lines would not fit onto the surface area of the local probe array.
  • Another scheme which is described by reference to Figure 9, can be used in such a situation.
  • the tips 90 of a 2-dimensional 1000 x 1000 local probe array are schematically depicted.
  • Read/write lines 91.x with read amplifiers 93.x and write amplifiers 92.x are indicated on the left hand side of the local probe array.
  • this storage device comprises 1000 select lines 95.x. According to this scheme, only N read/write lines and N select lines, i.e.
  • the storage device comprises a plurality of sub-arrays each having its own and mechanically independent local probe array.
  • the sub-arrays are arranged in banks and pages for receiving data bits to be stored and for retaining data bits from said devices.
  • the storage device comprises a plurality of read/write lines connecting to said local probes for transferring data bits thereto and therefrom.
  • a connector is coupled to said read/write lines in order to couple the storage device to the computer system.
  • the whole storage devices is placed inside a protective enclosure.
  • a memory controller is in addition employed to control access to said storage device and its sub-arrays, to synchronize data exchange, and to perform a memory check at power-on.
  • This memory controller might either comprise the data management means according to the present invention or might interact with such data management means via a serial or parallel interconnection bus.
  • the present storage device might further be connected to a Static Random Access Memory (SRAM) buffer for storing a row of data from said storage device.
  • SRAM Static Random Access Memory
  • the above memory controller would in this case also interact with the SRAM to load and select it.
  • Such a SRAM can also be used as temporary memory for clean-up.
  • the present storage devices are very well suited for use as video storage. For example, 64-bit words can be stored and retrieved very fast. If the storage device is linked to the image processor via a high speed bus systems, e.g. an optical bus, images can be processed and displayed in a fast and consecutive manner.
  • a high speed bus systems e.g. an optical bus
  • Storage devices as described above have an enormous storage capacity. Depending on the computer or system in which such a storage device is used, it might be sufficient, if a clean-up and data compression are carried out once a day, during night or weekend, or if no program currently takes access to the storage.
  • data management means are either integrated into one of the levels 1 - 3, or are carried out as separate unit. If this data management means determines that the storage device is almost full, or that there are many fields which comprise obsolete data, a clean-up process is initiated. Depending on the implementation the clean-up process is started only if the data management system realizes that neither the keyboard nor any application program is active. In a portable computer the clean-up process might be started if the computer is in a stand-by mode.
  • the storage medium might also be heated, illuminated, de-magnetized or the like to erase information.
  • either the cantilever array has to be flipped away, or parked at a safe distance such that the storage medium can be accessed from above. It is also possible to access the storage medium from underneath to erase information.
  • a resistive layer could for example be attached to the storage medium's backside. By applying a voltage to this resistive layer, the temperature of the medium could be increased. Depending on the storage medium used, such a temperature treatment leads to a removal of perturbations.
  • each local probe of a local probe array might be assigned to several storage sections. Assuming that there are ten storage sections assigned to each local probe of a local probe array having ten such local probes, the first ten storage sections could be accessed by these ten probes in parallel. If one of these ten sections is filled up, the whole local probe array is moved so as to access the next ten storage sections, and so on. The read access to information stored in storage sections which are currently not acted upon by said local probe arrays is slowed down, because the whole local probe array needs to be moved over a 'larger' distance before the respective storage sections can be reached by the local probes.
  • the present invention is well suited for use in a multiprocessor environment.
  • the present storage device could be partitioned into multiple autonomous sub-arrays. Each such sub-array might then be assigned to a particular processor of the multiprocessor systems.
  • Other sub-arrays of the storage device might be shared such that results of certain computations are made available to all processors. In these shared sub-arrays the application program can be stored also.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Molecular Biology (AREA)
  • Semiconductor Memories (AREA)
  • Storage Device Security (AREA)

Abstract

La présente invention concerne un dispositif de stockage comprenant une matrice de sondes locales (72) et un support de stockage (70) comprenant une matrice de zones de stockage (71). La matrice de sondes locales (72) se trouve en face du support de stockage (70), de telle sorte que chaque sonde locale (73) de la matrice de sondes locales peut être explorée au-dessus de la zone de stockage correspondante (31, 40, 71). Le dispositif de stockage comprend en outre des moyens (RF, 44; CF, 45) permettant de distinguer entre les informations (41) qui doivent être effacées d'une première section du support de stockage et les informations, dans cette section, qui ne doivent pas être effacées, des moyens permettant de copier de façon sélective dans une mémoire, de préférence une autre section du même support (32), les informations ne devant pas être effacées, et des moyens permettant d'effacer entièrement la première section.

Claims (30)

  1. Dispositif de stockage comprenant :
    un support de stockage (10) avec plusieurs sections de mémoire, sur lequel des données peuvent être enregistrées sous la forme de perturbations (12),
    une matrice de sondes locales (20) disposée en face dudit support (10) pour que ses sondes (14) balayent ledit support (10),
    un moyen pour obtenir des signaux de chacune desdites sondes quand elles balayent lesdites perturbations, et
    un moyen pour écrire des perturbations sur ledit support, et
    un moyen pour effacer une section entière,
    ledit dispositif étant caractérisé en ce qu'il comprend en outre
    un moyen pour distinguer les données à effacer de ladite section dudit support et les données de cette section qui ne doivent pas être effacées,
    un moyen pour copier sur une mémoire, de manière sélective, lesdites données qui ne doivent pas être effacées, de préférence une autre section dudit support.
  2. Dispositif de stockage selon la revendication 1, dans lequel ledit moyen pour effacer
    est supporté par ladite matrice de sondes locales, et
    est disposé de manière à pouvoir effacer des sections entières dudit support de stockage en une fois.
  3. Dispositif de stockage selon la revendication 1, dans lequel ledit moyen pour effacer
    est situé sur un côté dudit support alors que ladite matrice de sondes locales est située sur son autre côté, et
    est disposé de manière à pouvoir effacer en une fois des sections entières dudit support de stockage.
  4. Dispositif de stockage selon la revendication 1, dans lequel ladite matrice de sondes locales (20) comprend un réseau un une ou deux dimensions de bras de leviers qui portent chacun une ou plusieurs sondes locales qui, soit restent à une certaine distance dudit support, soit fonctionnent en mode contact.
  5. Dispositif de stockage selon la revendication 1, dans lequel ladite matrice de sondes locales ou ledit support se déplace en boucle fermée de sorte que chaque sonde balaye une certaine section dudit support de stockage.
  6. Dispositif de stockage selon la revendication 1 ou 5, dans lequel ledit support est divisé en de multiples champs de mémoire qui sont chacun balayés par au moins une sonde locale correspondante.
  7. Dispositif de stockage selon la revendication 1, comprenant un moyen de gestion de données qui distingue les données à effacer de ladite section dudit support et les données qui, dans cette section, ne doivent pas être effacées, en analysant des pointeurs ou des repères qui identifient lesdites données à effacer.
  8. Dispositif de stockage selon la revendication 7, dans lequel ledit moyen de gestion des données compare la quantité de données à effacer d'un premier champ de mémoire, à la quantité d'un autre champ de mémoire pour déterminer, en se basant sur des règles définies au préalable, quel champ de mémoire doit être effacé en premier.
  9. Dispositif de stockage selon la revendication 7, dans lequel ledit moyen de gestion de données utilise un algorithme génétique ou du voyageur de commerce.
  10. Dispositif de stockage selon la revendication 7, dans lequel soit chaque champ de mémoire comprend lesdits repères qui désignent les bits dudit champ de mémoire qui doivent être effacés, soit ledit support de stockage comprend une table dans laquelle sont gardés à jour des pointeurs qui désignant les bits dudit champ de mémoire qui doivent être effacés.
  11. Dispositif de stockage selon la revendication 4, dans lequel lesdits bras de levier portent plusieurs sondes pour que des mots binaires entiers puissent être écrits sur ledit support ou lus sur ledit support.
  12. Dispositif de stockage selon la revendication 1, comprenant des actionneurs qui provoquent un mouvement de balayage latéral dudit support par rapport à ladite matrice de sondes locales ou, de ladite matrice de sondes locales par rapport audit support.
  13. Dispositif de stockage selon la revendication 1, comprenant des actionneurs qui basculent ou retirent partiellement ladite matrice de sondes locales d'une section dudit support qui doit être effacée.
  14. Dispositif de stockage selon la revendication 1, comprenant une plaquette qui porte des lignes d'adresses pour accéder en lecture/écriture auxdites sondes, ladite plaquette étant rabattue sur ladite matrice de sondes locales de sorte que chacune desdites lignes d'adresse soit couplée électriquement à la sonde correspondante.
  15. Dispositif de stockage selon la revendication 14, dans lequel ladite plaquette comprend une circuiterie de lecture/écriture.
  16. Dispositif de stockage selon l'une quelconque des revendications précédentes, dans lequel ledit support est divisé en de multiples sous-réseaux autonomes, ayant chacun de multiples champs de stockage et une matrice de sondes locales qui est indépendante des matrices de sondes locales des sous-réseaux adjacents.
  17. Dispositif de stockage selon l'une quelconque des revendications précédentes, dans lequel ledit support comprend un substrat semi-conducteur (10) recouvert d'une fine couche d'oxyde (15) qui est recouvert par une couche diélectrique (11.x) et où des perturbations sont créées en appliquant localement une polarisation au moyen d'une sonde de sorte que les charges soient emprisonnées dans ledit support.
  18. Dispositif de stockage selon la revendication 17, dans lequel lesdites sondes sont des pointes conductrices et dans lequel ledit support comprend un contact arrière avec ledit substrat semi- conducteur (10) pour que des charges soient introduites localement dans le support si une tension est appliquée entre une pointe et ledit contact arrière.
  19. Dispositif de stockage selon la revendication 1, dans lequel ledit support est composé de matériau ferroélectrique dans lequel les perturbations sont créées en le polarisant localement au moyen d'une tension appliquée auxdites sondes.
  20. Dispositif de stockage selon la revendication 19, dans lequel lesdites perturbations sont détectées par l'interaction d'un champ appliqué à une sonde et de la polarisation de ladite perturbation.
  21. Dispositif de stockage selon la revendication 19, dans lequel lesdites perturbations d'une section dudit support ou d'un champ de mémoire entier sont effacées en appliquant un courant ou une tension suffisamment importants auxdites sondes ou par un autre moyen d'effacement de données, afin de les utiliser en mode émission de champ.
  22. Dispositif de stockage selon la revendication 1, dans lequel ledit support est composé d'un matériau dans lequel des perturbations peuvent être créées en chauffant localement ledit support.
  23. Dispositif de stockage selon la revendication 22, où lesdites perturbations d'une section entière peuvent être supprimées en réchauffant la section entière.
  24. Dispositif de stockage selon la revendication 1, dans lequel ledit support de mémoire est composé d'un matériau organique, de préférence un polymère ou de la cire, ou des cristaux liquides.
  25. Dispositif de stockage selon la revendication 1, comprenant m sondes locales et n sections de mémoire étant assignées à chacune desdites m sondes locales, c'est-à-dire que le dispositif de stockage comprend m fois n sections de mémoire.
  26. Mémoire de masse comprenant plusieurs dispositifs de stockage selon les revendications précédentes et des moyens pour interconnecter ladite mémoire de masse avec un système informatique.
  27. Procédé pour effacer des données enregistrées dans un dispositif de stockage comprenant
    un support de stockage (10) avec plusieurs sections de mémoire, sur lequel lesdites données sont enregistrées sous la forme de perturbations (12),
    une matrice de sondes locales (20) disposée face audit support (10) de sorte que ses sondes (14) balayent ledit support (10),
    un moyen pour obtenir des signaux de chacune desdites sondes quand elles balayent lesdites perturbations, et
    un moyen pour écrire des perturbations sur ledit support,
    le procédé comprenant les phases suivantes :
    différencier des données à effacer sur une première section dudit support et les données de cette section qui ne doivent pas être effacées,
    copier dans une mémoire, de manière sélective, lesdites données qui ne doivent pas être effacées, de préférence une autre section dudit support, et
    effacer la première section entière.
  28. Procédé selon la revendication 27, où les données à effacer de ladite première section dudit support et les données de cette section qui ne doivent pas être effacées sont différenciées en analysant des pointeurs ou des repères identifiant lesdites données à effacer.
  29. Procédé selon la revendication 27, où la quantité de données à effacer d'un premier champ de mémoire est comparée à la quantité de données contenue dans d'autres champs de mémoire afin de décider quel champ de mémoire doit être effacé en premier.
  30. Procédé selon la revendication 27, où les données lues à partir d'un champ de mémoire qui doit être effacé sont comprimées avant d'être écrites dans ladite mémoire.
EP95925091A 1995-07-28 1995-07-28 Applications, dans le stockage de grande capacite, de matrices de sondes locales Expired - Lifetime EP0783748B1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IB1995/000594 WO1997005610A1 (fr) 1995-07-28 1995-07-28 Applications, dans le stockage de grande capacite, de matrices de sondes locales

Publications (2)

Publication Number Publication Date
EP0783748A1 EP0783748A1 (fr) 1997-07-16
EP0783748B1 true EP0783748B1 (fr) 2001-11-21

Family

ID=11004354

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95925091A Expired - Lifetime EP0783748B1 (fr) 1995-07-28 1995-07-28 Applications, dans le stockage de grande capacite, de matrices de sondes locales

Country Status (5)

Country Link
EP (1) EP0783748B1 (fr)
JP (1) JP3095249B2 (fr)
KR (1) KR100264634B1 (fr)
DE (1) DE69524112T2 (fr)
WO (1) WO1997005610A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20020054111A (ko) * 2000-12-27 2002-07-06 오길록 1차원 다기능/다중 탐침 열을 이용한 고속/고밀도 광정보저장장치
US6515898B2 (en) * 2001-03-13 2003-02-04 Paul Scherrer Institut (Psi) Memory element, method for structuring a surface, and storage device
CN100411038C (zh) * 2002-09-11 2008-08-13 国际商业机器公司 探针存储装置及在探针存储装置中检测数据的方法
US6982898B2 (en) 2002-10-15 2006-01-03 Nanochip, Inc. Molecular memory integrated circuit utilizing non-vibrating cantilevers
JP2005004890A (ja) 2003-06-12 2005-01-06 Yasuo Cho 針状部材を用いたデータ記録再生装置およびデータ記録再生方法
US6763705B1 (en) * 2003-06-16 2004-07-20 Ut-Battelle, Llc High throughput microcantilever detector

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4122530A (en) * 1976-05-25 1978-10-24 Control Data Corporation Data management method and system for random access electron beam memory
US4064558A (en) * 1976-10-22 1977-12-20 General Electric Company Method and apparatus for randomizing memory site usage
EP0307210A3 (fr) * 1987-09-10 1991-05-15 Seiko Instruments Inc. Appareil enregistreur de mémoire
DE3739161C2 (de) * 1987-11-19 2000-06-15 Grundig Ag Verfahren zur Aufzeichnung und Wiedergabe von Informationssignalen auf ein bzw. von einem Aufzeichnungsmedium
JPH0298896A (ja) * 1988-10-05 1990-04-11 Olympus Optical Co Ltd 記憶装置
US5144581A (en) * 1989-02-09 1992-09-01 Olympus Optical Co., Ltd. Apparatus including atomic probes utilizing tunnel current to read, write and erase data
JPH0393059A (ja) * 1989-09-05 1991-04-18 Fuji Electric Co Ltd 光磁気ディスクオペレーティングシステム
JPH03104421A (ja) * 1989-09-19 1991-05-01 Hitachi Ltd データ圧縮方式、データ圧縮装置およびデータ復元装置
JPH04129043A (ja) * 1990-09-19 1992-04-30 Canon Inc プローブユニット、該プローブユニットを備えた情報処理装置及び情報処理方法
US5216631A (en) * 1990-11-02 1993-06-01 Sliwa Jr John W Microvibratory memory device
GB2251323B (en) * 1990-12-31 1994-10-12 Intel Corp Disk emulation for a non-volatile semiconductor memory
JP2794348B2 (ja) * 1991-06-21 1998-09-03 キヤノン株式会社 記録媒体、その製造方法、情報処理装置
JP3546432B2 (ja) * 1992-12-04 2004-07-28 ソニー株式会社 編集装置

Also Published As

Publication number Publication date
DE69524112T2 (de) 2002-08-01
WO1997005610A1 (fr) 1997-02-13
JP3095249B2 (ja) 2000-10-03
JPH09511863A (ja) 1997-11-25
KR100264634B1 (ko) 2000-10-02
EP0783748A1 (fr) 1997-07-16
DE69524112D1 (de) 2002-01-03
KR970706568A (ko) 1997-11-03

Similar Documents

Publication Publication Date Title
US5835477A (en) Mass-storage applications of local probe arrays
US6404647B1 (en) Solid-state mass memory storage device
EP1530210B1 (fr) Appareil d'enregistrement/reproduction d'informations et milieu d'enregistrement
US5491338A (en) High resolution imaging and measuring dynamic surface effects of substrate surfaces
US5412641A (en) Information recording/reproducing apparatus for recording/reproducing information with probes
JP3073616B2 (ja) マルチプローブを具備する情報処理装置
EP1371061B1 (fr) Appareil et procede de stockage et de lecture de capacites de donnees elevees.
US6665258B1 (en) Method and apparatus for recording, storing and reproducing information
WO1997044780A1 (fr) Support d'enregistrement en alliage a memoire de forme, memoires basees sur ledit support, et procede permettant d'utiliser lesdites memoires
EP1151437A2 (fr) Support memoire moleculaire et circuit integre de memoire moleculaire
JP2006503399A (ja) 非振動カンチレバーを用いた分子メモリ集積回路
EP0783748B1 (fr) Applications, dans le stockage de grande capacite, de matrices de sondes locales
US8189450B2 (en) Method and apparatus providing high density chalcogenide-based data storage
JP3023728B2 (ja) プローブ構造体、記録装置、情報検出装置、再生装置及び記録再生装置
JP2942013B2 (ja) 記録及び／又は再生装置
JPH09147433A (ja) 情報記録再生方法およびその装置
JPH04129043A (ja) プローブユニット、該プローブユニットを備えた情報処理装置及び情報処理方法
JPH0438636A (ja) ランダムアクセスメモリ
JPH06251438A (ja) 情報処理装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19970326

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 20010118

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20011121

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

REF Corresponds to:

Ref document number: 69524112

Country of ref document: DE

Date of ref document: 20020103

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

EN Fr: translation not filed
26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: 746

Effective date: 20080704

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20140725

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20140729

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69524112

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20150727

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20150727